CASE 41

Rule 12, On the Same Tack, Not Overlapped
Rule 18.2(a), Rounding and Passing Marks and Obstructions: Giving Room; Keeping Clear: Overlapped – Basic Rule
Definitions, Obstruction

If an obstruction can be passed on either side by two overlapped boats, the right-of-way boat, if she chooses to pass it to leeward, must give room to the other. If the right-of-way boat chooses to pass it to windward, she is entitled to room to do so, and the other boat must keep clear. There is no obligation to hail for room at a mark or obstruction.

Question 1
BW, the windward boat, is subject to rules 11 and 17.2 in her obligations to BL. Does the proximity of the third, slower boat, A, change the relationship between BW and BL to one in which rule 18 comes into force when they overhaul A?

Answer 1
Yes. With respect to A, both boats astern must keep clear of her under rule 12. However, A also is an obstruction to both, as the last sentence of the definition Obstruction makes clear. When they are ‘about to pass’ A, still overlapped, rule 18 will come into effect. If BL then chooses to pass A to leeward, rule 18.2(a) will require her to give room to BW, as inside boat, to do likewise. BW is not required to take the room provided, and may pass A to windward, keeping clear of her under rule 12 and then rule 11. If BL chooses to pass to windward of A, then rule 18.2(a) requires BW to give BL room to pass A and both rule 18.2(a) and rule 11 require BW to keep clear of BL. Rule 12, and later rule 11, require BL to keep clear of A.

Question 2
Does BW have to hail for room to pass to leeward of A, or would BL risk disqualification by not automatically giving room?

Answer 2
BW is not required to hail for room, although that is a prudent thing to do to avoid misunderstandings. Rule 18.2(a) requires BL to give room to BW when they both pass to leeward of the obstruction, whether or not BW hails for room.

RYA 1977/6